Dear Liz: I’m a single mom with three kids. My mortgage is $1,700. My other monthly bills include $355 for a car loan, $755 for school tuition, $350 for utilities, $790 for credit cards, $200 for gas, $208 for braces and $235 for a 401(k) contribution. This leaves no money for food. I get no child support. How can I pay down my credit card debt? I don’t have any money for a baby sitter or I could get a second job.

Answer: The way you pay down credit card debt is by reducing expenses and increasing income to free up extra cash. If that’s not possible, you may need to consider bankruptcy, given the amount of debt you’re carrying.

If you’re paying only the minimums on your credit cards, that monthly bill indicates you have close to $40,000 in credit card debt. Since you can’t cover your basic expenses, you’re probably adding to that debt pile every month. That needs to stop.

You don’t say why you aren’t receiving child support, but if the father isn’t dead or disabled he should be helping to support his kids. Your state has an enforcement agency that can help you. Child support enforcement is often part of a state’s social services department, although it may also be offered by the state attorney general or its revenue (tax) department.

One obvious, if painful, place to trim is private school tuition. If the school can’t offer you financial aid, you should consider placing your kids in the best public school you can manage.

What you don’t want to do is trim your retirement plan contribution. You’re probably getting a company match, which is free money you’ll need to sustain yourself in retirement.

In general, your “must have” expenses — shelter, transportation, food, utilities, insurance and minimum loan payments — should equal no more than 50% of your after-tax income. If your must-haves exceed that level, it will be tough to make ends meet, particularly if you’re trying to pay off debt and save for the future.

Dear Liz: I’m beginning to realize that I have no idea how to budget. I make plenty of money but always seem to come up short. I’m trying to find the best person to help me make a budget. Do I talk to a CPA or a financial counselor? If so, how do I find the right person?

Answer: Budgeting has three basic steps: figuring out where your money is going now, deciding where you want it to go in the future, and monitoring your spending to make sure you stay on track with those goals.

Just because something is simple doesn’t mean it’s easy, however. People often fail to account for predictable but irregular expenses, such as car repairs. Once those crop up, the budget is thrown into disarray and people often give up on the spending plan.

Budgeting also can be difficult if you’re overspending on your overhead. If too much of your income is going for basic expenses, you may not have enough left over to live a comfortable life, pay off debt and save for the future, regardless of how many other expenses you trim. People who spend too much on shelter (mortgage or rent) and transportation (car payments and attendant costs) in particular often find they can’t create a balanced budget. Your “must haves” — shelter, transportation, food, utilities, insurance and minimum loan payments — ideally should be 50% or less of your after-tax income to create a workable budget.

Some people find that online solutions, such as the Mint.com financial tracking site, are enough to get them started with a budget. Other people need hands-on help. If your tax pro or financial advisor has experience helping people create and monitor budgets, that’s certainly one place to turn. Otherwise, check to see whether your local community college offers basic money management courses. Another option is a nonprofit agency affiliated with the National Foundation for Credit Counseling at http://www.nfcc.org. Many of these agencies offer classes or hands-on help creating budgets.